Press fit pinless latching shroud

ABSTRACT

There is disclosed a press-fit pinless latching shroud. The latching shroud retains a connector to a pinfield with two flexible interlocking arms. The connector may be removed from the shroud by the user by disengaging the flexible arms from the connector. The latching shroud mounts to the pinfield by creating an interference fit between a portion of the pinfield and a series of matching holes in its base.

This application is a continuation application under 37 C.F.R. 1.62 ofapplication Ser. No. 08/005,487 filed Jan. 19, 1993, entitled "Press FitPinless Latching Shroud", now abandoned and which is a continuation ofapplication Ser. No. 07/644,892 filed Jan. 23, 1991, entitled "Press FitPinless Latching Shroud," now U.S. Pat. No. 5,180,312 issued Jan. 19,1993.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to the field of electrical connectors.More particularly, the present invention relates to an apparatus andmethod for attaching an electrical connector to a pinfield.

BACKGROUND OF THE INVENTION

Computer hardware designers regularly create systems with subcomponentprinted circuit boards ("PCB's"). These PCB's must be connectedelectrically to other subassembly PCB's and to a common structure or"motherboard" to function properly. Currently, those electrical signalsthat must be routed on or off a particular PCB are done so on the edgeof the PCB in rows of small sockets which are attached along one edge.The electronic circuits on the PCB's terminate at these sockets. Thesockets are designed to connect, typically, to two or four rows of pinson a motherboard. The mating pins carry through the motherboard tointernal connections, and terminate, on the reverse side, in matchingpins. Necessary connections between PCB's on the same motherboard aremade internally, within the motherboard. Connections between PCB's ondifferent motherboards are made externally, by attaching cables from pinto pin. Each cable typically contains a dozen individual circuits andterminates in a dozen sockets. Motherboards are designed to acceptnumerous PCB's resulting in many long rows of dense connecting pins.

At least one problem arises when PCB's from different motherboards areconnected to one another by cable. Reliability requirements mandate thateach external cable must be secured to the motherboard to avoidinadvertent disconnection.

One approach to this problem could be to increase the normal forcebetween the pin and cable socket. This could be accomplished bydecreasing the size of the socket or by increasing the size of the pin.Although the resulting connection would be secure from unintentionalseparation, it would be equally resistent to intentional separations bythe user. The individual pins would also be susceptible to damage by theexcess force required to intentionally make or break the connection. Asa result, this solution is not practical.

A practical method of securing a cable to a pin field is to mechanicallyconnect or latch the cable to the motherboard. Although the pin tosocket normal force may be kept small, the size of the latchingmechanism becomes critical on a crowded motherboard. Conventionaldevices use screws or latching end-brackets to secure the cable to themotherboard. These mechanical means are typically mounted at either endof a pinfield. The presence of the locking mechanism therefore requiresthat the pin fields have gaps in them to accommodate the hardware.

A related solution is to route the circuits within the motherboard to anarea where there are no PCB pins. The routed circuits can then emergefrom the motherboard for cable attachment to another set of pins and tothe latching hardware.

Neither of these latter two options is completely satisfactory givenpresent component densities. Increasing the parts count results inhigher numbers of pins per PCB, more PCB's per motherboard, and littlespare room on current motherboards.

Consequently, there is a need in the art for a cable latching mechanismthat is secure against inadvertent separation, that allows the user toeasily make or break a connection when desired, and that does notrequire additional space on the motherboard to mount.

SUMMARY OF THE INVENTION

In accordance with the present invention, a pinless shroud is providedthat substantially eliminates or reduces disadvantages and problems withprior connectors.

A shroud for retaining a connector on a pinfield is disclosed. Theshroud mounts on a portion of the pins by creating an interference fitbetween the shroud base and the pins. The connector is demateblyconnected to the shroud by flexible arms extending from the base. Thearms engage the connector when the two are mated. The arms may beexpanded to release the connector when desired. A spacing member betweenthe shroud base and the base of the mating pins ensures proper heightalignment between the connector and the pinfield.

Accordingly, it as an advantage of the present invention that animproved cable retention mechanism is provided. The mechanism engages aconnector with two interlocking arms spaced across the width of thepinfield. The arms flex outward to accept the connector upon insertionand may be easily expanded by the user to remove the same connector. Thenormal force between the pin and socket can therefore be kept at a lowlevel.

Another advantage of the device is its adaptability to various pinheights. A spacing member is either attached to the base of the deviceor is inserted between the base and the surface from which the pinsprotrude. The member may be easily modified to cause the pin to properlyprotrude from the base of the device. The proper protruding pin lengthwill insure a reliable connection between the pins and connector.

Yet another advantage of the device is its small footprint wheninstalled. The connector may be placed on a continuous row of pinswithout modification or harm to the pinfield. The device also may besubstantially shorter or longer than the connector that it retains.

Yet a final advantage of the device is its general adaptability tovarious connector widths. A single device is able to retain a singlepartial-width or full-width connector or a combination of partial-widthconnectors within the same unit. The disclosed device may also be usedin conjunction with other similar devices to retain long connectorswhich would otherwise be unmanageable with a single shroud.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be derived byreferring to the detailed description and claims when considered inconnection with the accompanying drawings, wherein like referencenumbers refer to similar items throughout the drawings, and:

FIG. 1 depicts a latching shroud typical of the prior art;

FIG. 2 shows a continuous pinfield with three latching shrouds mountedthereon, constructed in accordance with the present invention;

FIG. 3 also depicts a latching shroud constructed in accordance with thepresent invention;

FIG. 4 shows a sectional view taken along the line 4--4 of FIG. 3; and

FIG. 5 shows a perspective view of one embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts a latching shroud 10 typical of the prior art. Latchingshroud 10 accepts connector 12 for connection to a pinfield (hidden) ofdimension w×1. Latching shroud 10 is coupled to a motherboard (notshown) directly, e.g. by adhesive or screws, or indirectly, by aninterference fit between the base of the latching shroud 10 and thepinfield. Connector 12 is held in place by two latches 14. The latches14 may pivot outward on axes 16 for removal of the connector 12 whendesired.

One problem created by the prior art is its inefficient use of space onthe motherboard. Connector 12 mounts to a pinfield only of size w×1 butthe latching shroud 10 effectively occupies a pinfield of size w×1'.This design also precludes the use of the latching shroud on acontinuous row of pins. Gaps must exist in the pinfield to accept thefootprint of the two latches 14.

Another problem of the prior art is its high degree of complexity yetlow flexibility. Shroud 10 contains several parts which typicallyrequire assembly during manufacture but is matable to only oneparticular connector size, here w×1. Also, latching shroud 10 isfabricated as a large single piece with two latching brackets. Thecentral section of latching shroud 10, however, is not necessary. Thetwo end areas of latching shroud 10 alone provide sufficient retentionstrength for connector 12.

FIG. 2 depicts an improved latching shroud 20 which retains a connector,such as connector 21, to a pinfield, such as pinfield 204. Pinfield 204projects from motherboard 206. A portion of pinfield 204 mates with aset of matching holes 22 in latching shroud 20. Shroud 20 has crossmember 24 in which are constructed holes 22. Latching shroud 20 issecured to pinfield 204 and, hence, to motherboard 206 by aninterference fit between holes 22 and pins 204. First flexible arm 210A,which is secured to base or cross member 24, has first wedged shoulder211. Similarly, second flexible arm 210B, which is secured to base orcross member 24, has second wedged shoulder 213. When connector 21 isinserted onto pinfield 204 between arms 210A and 210B, the first wedgedshoulder 211 and second wedged shoulder 213 move over and engageconnector shoulder 21A and thereby releasably secure connector 21 toshroud 20. Bottom legs 23 are used for spacing as will be discussed.

When latching shroud 20 is inserted on pinfield 204, those pins coveredby latching shroud 20 project through matching holes 22. Latching shroud20 does not need to be the same length as connector 21 to insure aproper connection. Shroud 20 can accommodate connectors of variouslengths. Connector 21 may be taller than, the same length as, or shorterthan latching shroud 20. Hence, not all pins that mate with connector 21pass through holes 22 of latching shroud 20.

Latching shroud 20 is designed to accommodate a full-width connector, apartial-width connector or a combination of partial-width connectors.Two arms 210 are angled inwards on latching shroud 20 to be able toretain a single partial-width connector. Catch 205 is formed on orsecured to a distal end of arms 210 to help retain a singlepartial-width connector. If instead, two connectors are installed inlatching shroud 20, arms 210 flex outwards slightly to accommodate theirwidth. Latching shroud 212, for instance, is mated with a 0.1 inch×0.1inch pinfield 204 and accommodates two 2-pin-width connectors 214.Latching shroud 216 is mounted on pinfield 204 and accepts a single2-pin-width connector 220.

Latching shroud 216 also contains a thin end member 218 connecting thetwo arms on one side. Member 218 provides a convenient reference pointfor the user to align connector 220 with the appropriate pins. Themember 218 thus serves to "index" for future reference a set of desiredpins on which a connector is to be inserted.

The disclosed invention is adaptable to a wide variety of regular orirregular pinfield geometries. FIG. 3, for instance, depicts latchingshroud 30 mounted on a pinfield 301 of wire-wrap tails protruding frombackplane connector or motherboard 302. The pinfield forms a 0.1inch×0.2 inch matrix. FIG. 2 depicts a regular 0.1 inch×0.1 inchpinfield. Shroud 30 of FIG. 3 is fabricated with straight arms becauseit is designed to accept a single two-pin-width connector (such asconnector 21, FIG. 2). The arms, therefore, need not taper inwards as inFIG. 2.

The disclosed invention is also adaptable to mate unusually longconnectors and continuous pinfields. Shrouds such as 20, 212 and 216,may be combined to provide pin alignment, height adjustment (discussedlater) and cable retention over the entire length of a connector. Shroud216 could be mounted on a target pinfield to indicate the first (orlast) row of pins to mate with the connector. Another shroud, such asshroud 20, could be mounted further down (or up) the pinfield to providesupport and guidance for the connector near its midpoint or other end.The two shrouds need not be contiguous but may be separated by a row orrows of bare pins. In a similar manner, any number of shrouds may becombined to provide support and guidance for any length of connector.

FIG. 4, a cross section taken through the pinfield of FIG. 3, depictshow latching shroud 30 is properly positioned above motherboard 302. Byadjusting the height, h1, of spacing leg 23, the height, h, of pins 301protruding through holes 208 of latching shroud 30 can be adjusted. Thevalue of h must be controlled to insure a proper connection between theconnector (such as connector 220, FIG. 2) and pins 301. If h is toogreat, (h1 too small) the connector may be damaged when the pinfield ismated with the connector. If h is too small, (h1 too great) a properelectrical connection may not be made.

Member 23 can take several forms. For instance, member 23 could be theextension of each arm 210, as shown in FIG. 2. Member 23 could be asmall washer or sets of washers 400 inserted over mating pins 301between motherboard 302 and latching shroud 30. Member 23 could also bea flat spacer placed on motherboard 302 before the latching shroud isinserted onto the pinfield.

FIG. 4 also depicts more clearly how holes 22 engage pins 301. Latchingshroud 30 contains an enlarged opening 401 to initially guide pins 301into the holes 22. Each hole 22 then tapers to a restricted passagewayto create an interference fit with a mating pin 301.

FIG. 5 depicts a latching shroud 50 designed to retain two ten-pinconnectors (not shown) on a 0.1 inch×0.1 inch pinfield (not shown).Latching shroud 50 is inserted onto a pinfield such that individual pinsprotrude through holes 52. An interference fit between the protrudingpin and holes 52 retains the shroud 50 to the pinfield as described withrespect to FIG. 4. Corner legs 54 act to space latching shroud 50 abovethe surface (not shown) from which the pinfield projects. Corner legs 54thereby ensure a proper connection between pinfield and connector asexplained with respect to FIG. 4. The two connectors are inserted ontothe left and right columns of pins in latching shroud 50. Guidingmembers 56 align each connector with the appropriate group, or matrix,of pins. The center column of pins projects through the center column ofholes but does not mate with any connector. Brackets 58 retain theconnectors when mated to the pinfield. The right bracket has beenremoved from latching shroud 50 for clarity. Brackets 58 flex outwardswhen the connectors are initially mated to the pinfield and may be laterexpanded by the user by pressing outward on tab 60 to release theconnectors.

Bracket stops 62 prevent brackets 58 from being flexed outwards(hyperflexed) beyond the elastic limit of the shroud material andprovide support for guiding members 56. Cavities 66 on each end ofshroud 50 allow shroud 50 to be mounted on a continuous pinfield byallowing a row of pins immediately above and below the shroud 50 toproject normally. Without cavities 66 the footprint of bracket stops 62would crush the row of pins below them. Side cut-outs 64 on each side ofbracket 50 are incorporated into the design to allow efficient singlepiece fabrication of shroud 50.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

What is claimed is:
 1. A shroud for retaining at least one connector,each connector containing a plurality of sockets, the sockets matingwith a plurality of pins protruding from a surface, the connector havinga length and a width, the pins part of a continuous pinfield formed ofpins regularly spaced along the length of the pinfield, the pinfieldhaving a length and a width, each of said shrouds further comprising:abase member for securely mounting said shroud on a portion of saidpinfield, said base member having a length and a width, said base memberformed to receive said connector even if said connector has a lengthgreater than said length of said base member, said base member mountableon said pinfield even if said length of said pinfield is larger thansaid length of said base member and mountable over differentcombinations of said pins along the length of said continuous pinfield;a first arm attached to a first longitudinal edge of the base member andhaving a first wedged shoulder on a distal end of the first arm; asecond arm attached to a second longitudinal edge of the base member andhaving a second wedged shoulder on a distal end of the second arm; thefirst arm and the second arm being urged towards each other so that whenthe connector is inserted into the shroud to the point where the wedgedshoulder of each arm reaches a connector shoulder on the connector, thefirst wedged shoulder and second wedged shoulder move over the connectorshoulder and thereby releasably secure the connector to the shroud;andwherein the plurality of pins of the pinfield are arranged in rows,and further comprising a thin end member attached to a lateral edge ofthe base member for assisting with alignment of the shroud with respectto a desired row of the pinfield.
 2. The shroud of claim 1 wherein thefirst arm and second arm are configured to accommodate one or twoconnectors by having adequate flexibility to allow the insertion of twoconnectors and configured to urge inwardly the first arm and second armto engage the connector shoulder of the connector even when only oneconnector is inserted.
 3. The shroud of claim 1 further comprising ameans for spacing the base member a predetermined distance from thesurface of the pinfield.